Constant current circuits are very useful in integrated circuit (IC) design. Many forms of current regulation and control circuitry have been developed. For example, U.S. Pat. No. 3,629,691 discloses an IC current source useful in controlling the bias on current sink transistors. U.S. Pat. No. 4,063,149 discloses a current regulating circuit that can be used to bias a plurality of current sink transistors. Both of these prior art circuits employ current amplifiers connected to a pair of transistors operating at different current densities so that the current flowing in the two transistors is regulated. The circuits develop a bias that when coupled to a transistor will cause it to sink a constant current. In both of these prior art circuits the current used in the control circuit is substantial and both circuits require additional means for power-up starting.